1. Different working principles
Gas welding is a welding method that uses the flame produced by the mixed combustion of combustible gas and combustion-supporting gas as a heat source to melt the welding parts and welding materials and achieve atomic bonding. Electric welding uses electrical energy to apply pressure, heat, or both, with or without filler material, to achieve atomic bonding of the weldment.
2. The basic operating procedures are different
The main processes of gas welding include ignition, flame adjustment and flameout, and superposition of flat welding waves.
The main processes of electric welding include arc ignition, strip transportation and welding end.
Welding methods are usually divided into fusion welding, pressure welding and brazing according to the different heating and pressure conditions during welding.
Fusion welding is the heating of the metal at the joint of the weldment to a molten state during the welding process. Welding is generally done without pressure. During the welding process, a heat source rapidly melts the metal in the weld and adds filler metal if necessary. The molten pool extends as the heat source moves and cools to form a weld.
According to different electric heating methods, it can be divided into electroslag welding, arc welding, laser welding and electron beam welding. Fusion welding is widely used in various welding methods, especially arc welding.
Pressure welding is a welding method that joins weldment joints under pressure (with or without heating). According to the different pressure welding mechanisms, pressure welding can be divided into high-frequency welding, diffusion welding, resistance welding, friction welding, ultrasonic welding, etc. Among them, resistance welding is the most widely used.
Most pressure welding methods do not have a melting process, and there is no problem of burning of beneficial alloy elements such as fusion welding or infiltration of harmful elements in the weld. However, the welding conditions of pressure welding are harsh and the scope of application is narrow.
Brazing is a welding process in which a material with a melting point lower than the weldment is melted and adhered to the weldment, and the joints of the weldment are connected together after cooling. Generally it can be divided into gas welding and electric welding.
Gas welding, also known as burning welding, uses acetylene gas as the combustion source, mixed with oxygen, and then ignited to weld metal parts with a welding gun. Some unique metals are easily oxidized (such as aluminum) and require inert gas protection, such as argon welding.
